Need To Make A Team Umizoomi Car Cake??? Help Please

AFor my sons birthday I want to make a 3D team umizoomi car cake with milli geo and bot sitting inside. The only kind of cake I have ever made is a regular sheet cake or a layered cake.. I need all the help I can get, on what kind of decorating tools I will need and how to actually carve the cake. O also how to do the fondant as i have never worked with that either.. Thanks in advance!!